It is well known to provide non-grassed surfaces for training and competition in equestrian sports. A wide variety of such surfaces have been suggested and used over the many years in which non-grassed surfaces have been in use for equestrian sports.
One known form of riding surface is based on finely chopped PVC (from used electrical cable insulation material). However, this surface also has the disadvantage of being rather loose and cost is rather high.
Another known surface is based on ashes from power stations. The surface provides good drainage when newly laid in wet weather, but in dry conditions the surface is dusty and becomes compacted and too hard, especially after prolonged use.
Another known surface, commonly known as hard porous, comprises a water bound grit/sand/clay mixture, normally laid over a drainage layer of coarser material. Such a surface has the disadvantage of inadequate cushioning and is excessively abrasive. The surface material also has a tendency to gradually lose its structure and permeability over time. In dry weather dust is a problem.
Other riding surfaces include synthetic materials intended to imitate real turf. Such synthetic turf may be in filled with a top dressing of sand. Such a surface is expensive to install, and expensive and difficult to maintain and repair.
It is well known to provide surfaces for horse riding based on sand or other particulate materials. The principal problem with sand as a surface is that it has a tendency to be too loose or too deep. Conversely, if the conditions are dry the riding surface can become too hard which leads to a risk of leg injuries to the horses. If sand is completely dry, however, the riding surface can become extremely loose, which leads to a risk of leg injuries to the horses.
U.S. Pat. No. 4,819,933 discloses a surface is for use in equestrian events formed of a blend of sand and fibres in which the fibres are polymeric fibres.
Other means for production of artificial riding surfaces are described in U.S. Pat. No. 4,433,813, which provides the surface from wood chips.
NL 1004801 describes a riding surface comprising plastic fibres.
NL 9300602 describes bonded webs of fibres which are generally organic.
EP-A-136747 describes an artificial grass field of which the substructure is based on sand. Thus, this structure is different from a standard sand-based riding surface, of which the sand forms the surface which is exposed and on which the horses are ridden. According to this publication, the substructure for the artificial field is a blend of sand and at least 1 wt/% fibrous material, which can be organic fibres or artificial fibres such as polypropylene fibres or nylon fibres. Inorganic fibres such as glass fibres are also mentioned. These surfaces are described as useful for football, hockey, tennis and for riding schools.
Another document concerning substructures for artificial sports surfaces is WO 97/21876 in which sand or other granular material is blended with fibres. These can be mineral fibres such as glass fibres.
GB 217471 A relates to a material for the construction of tennis courts and the like, which consists of a gritty material, such as ground brick, and asbestos (which is a type of natural crystalline silicate fibre). In contrast with stone fibres (which are a class of man-made vitreous fibre), the use of asbestos can give rise to health concerns.